Carrion, 41, has been a Baltimore district judge since 1995 and was the first Hispanic American to serve on the Maryland bench.

She worked previously as an assistant state attorney general and in the Russell and Thompson law firm, which later merged with Piper and Marbury. She fills the vacancy created by the retirement of Judge Mabel E. Houze Hubbard.

Allison, 48, has been an assistant U.S. attorney in Baltimore since 1991.

She also has worked for the Justice Department in Washington, for the U.S. Environmental Protection Agency and in private practice.

Allison is replacing Judge Edward J. Angeletti, who will retire next week.